Update checkout action to use v3 and upgrade to node16. Ref #244

[soleo]

https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/

GitHub is sunseting nodeJS 12 for actions.

Similar approach like https://github.com/actions/checkout/pull/689/files

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[bkendall]

This looks very reasonable. Would you mind catching it up with main and updating the branch? Thanks!

[soleo]

Sure, @bkendall . I just rebased it with the main branch. If you wanna see a working demo, you could also check out https://github.com/soleo/xinjiangshao.com/blob/master/.github/workflows/firebase-hosting-pull-request.yml for reference

[bkendall]

oh this nonsense. The tests that require secrets are going to fail because they won't work from a fork. I'll take care of that once you remove the tsconfig thing :)

[bc-micah]

Oops - sorry about "Approving" the PR. That was a mistake, please dismiss the review. Thank you